Pi square is nearly 10

[freediver]

https://mihai.page/pi-square-is-10/

[lifthrasiir]

The second fact, pi^2 ~= g, is famous enough that it has a separate section in Wikipedia [1].

[1] https://en.wikipedia.org/wiki/Mathematical_coincidence#Gravi...

[yehoshuapw → lifthrasiir]

And https://xkcd.com/1047/

[hnfong → yehoshuapw]

Also https://xkcd.com/217/

[renyicircle]

My first thought was "well of course it is, since pi is a little larger than 3" but it was cool to see an actual derivation of how much pi squared differs from 10 as a nice, closed form series.

[Dwedit]

If you don't unblock scripts from cdn.jsdelivr.net.cdn.cloudflare.net, the math code won't work.

[verzali]

I remember discovering that pi x 10^7 is very close to the number of seconds in a year while at uni.

One of my tutors was convinced this had to be more than coincidence, but I always figured it was just chance and a nice but sometimes useful shortcut...

[tzs → verzali]

You might be able to send someone down an amusing (to observers) rabbit hole of wrongness by telling them it is not exact because Earth’s orbit is not perfectly circular.

[leni536]

This first became apparent to me when I got a slide rule. Pi is often marked on the various scales and an x^2 scale is often nearby the x scale.

[BrandoElFollito]

As an ex-physicist, pi^2 is 10. Like g.

I get it that this is a nice calculation with the Zeta function and everything, but 3 and a small something squared will be near 10 so it is 10.

[Lerc]

I was a little disappointed that the upper range of gravity on earth only goes to 9.8337. Just a little more and there would have been somewhere on earth that was an exact match.

It would have been the ideal (if chilly) place to start a cult.

[smitty1e]

The author wants tau=2*pi, but in the Greek alphabet, tau has one vertical stroke, and pi has two.

So, visually in Greek, pi=2*tau would seem an improvement.

Oh, well.

[Georgelemental → smitty1e]

Tau is tau over 1, pi is tau over 2. See also https://www.tauday.com/tau-manifesto#sec-conflict_and_resist...

[Razengan → smitty1e]

pi's prevalence instead of tau is one of the strongest indicators that we live in a suboptimal timeline.